Bug 391846. Fire correct text change events when a node is shown or hidden. r=surkov, sr=sicking, a=sicking

content/base/src/nsGenericElement.cpp

@@ -125,6 +125,11 @@
 #include "nsIXULDocument.h"
 #endif /* MOZ_XUL */
 
+#ifdef ACCESSIBILITY
+#include "nsIAccessibilityService.h"
+#include "nsIAccessibleEvent.h"
+#endif /* ACCESSIBILITY */
+
 #include "nsCycleCollectionParticipant.h"
 #include "nsCCUncollectableMarker.h"
 #include "nsCycleCollector.h"
@@ -2694,6 +2699,22 @@ nsGenericElement::doRemoveChildAt(PRUint32 aIndex, PRBool aNotify,
   NS_PRECONDITION(!aParent || aParent->GetCurrentDoc() == aDocument,
                   "Incorrect aDocument");
 
+#ifdef ACCESSIBILITY
+  // A11y needs to be notified of content removals first, so accessibility
+  // events can be fired before any changes occur
+  if (aNotify && aDocument) {
+    nsIPresShell *presShell = aDocument->GetPrimaryShell();
+    if (presShell && presShell->IsAccessibilityActive()) {
+      nsCOMPtr<nsIAccessibilityService> accService = 
+        do_GetService("@mozilla.org/accessibilityService;1");
+      if (accService) {
+        accService->InvalidateSubtreeFor(presShell, aKid,
+                                         nsIAccessibleEvent::EVENT_DOM_DESTROY);
+      }
+    }
+  }
+#endif
+
   nsMutationGuard::DidMutate();
 
   nsINode* container = NODE_FROM(aParent, aDocument);